Resilient control of master cam



RESILIENT CONTROL OF MASTER CAM Filed Oct. 22, 1958 INVENTOR HAROLD E.BALSIGER ATTORNEY S United States Patent RESILIENT CONTROL OF MASTER CAMHarold E. 'Balsiger, Waynesboro, Pa., assignor to Landis Tool Company,Waynesboro, Pa.

Filed Oct. 22, 1958, Ser. No. 769,023

Claims. (Cl. 51-101) The following is a specification in detail of aninvention in resilient control for a master cam. In general theinvention relates to an improvement in a machine for grinding camshafts, where the position of the cam shaft relative to the grindingwheel is varied as required by the shifting of a master cam controllingthe approach of the cam shaft to the grinding wheel.

The invention has particular reference to a machine for grinding camshafts as disclosed in the invention of Balsiger and Price, patented May27, 1941, No. 2,243,410.

In the patent, the cradle is rocked to separate the master cam androller by means of a piston operating against a spring. The pistoncompresses the spring as it passes through the entire movement ofseparation. The return of the master cam to engagement with the rolleris effected entirely by the spring which also returns the p1ston tostarting position.

It is therefore an object of this invention to provide means whereby theforce of the piston is applied to advance the cradle as well as retractit.

A further object is to provide a resilient connection between saidpiston and the means for operating the cradle when the master cam is tobe moved into engage ment with the follower.

A further object is to provide means whereby spring pressure is notexerted on the cradle arm until after the master cam engages the roller.

It is an object of this invention to provide novel means to effect anunimpeded advance of the master cam into contact with the usual followerroll.

It is a further object of the invention to maintain resilient pressureupon the advancing master cam and furthermore increase that pressure asthe master cam is brought into contact with the follower roll.

A still further object of the invention is to provide a movable supportfor the resilient compression means for applying pressure to the mastercam.

Among the objects of the invention is to permit a free retraction of theoperating means independent of the pressure applying arm.

Other objects of the invention will be evident from the followingdescription of the preferred form of the invention as illustrated insection in the accompanying drawing.

In brief, the objects of the invention are attained by providing aresilient means actuated by hydraulic or other power means, for applyingadvancing pressure against the rocker arm controlling the position ofthe master cam. This resilient means is supported by a movableabutmentso that the full force of the resilient ice means is appliedagainst the rocker arm and in fact increases with the advance of thelatter. The resilient means specifically is a compression spring. Thecompression is supplied by said power means acting through saidabutment. This has the characteristic of increasing the pressure onlyafter the master cam engages the follower.

The invention as shown on the accompanying drawing, is embodied in agrinding machine for cam grinders such as is disclosed in the patentabove identified and to which reference is made forthe general featuresof the structure.

Cam grinding machines of this type are provided with a headstock housing5 mounted upon the carriage 29 of the cam grinding machine.

This headstock housing has a longitudinally extending shaft 6. The shaft6 carries a follower roll 7.

A pivot shaft 8 also extends longitudinally of the carriage below thefollower shaft 6. The .pivot shaft 8 permits cradle 9 to oscillate.freely to the extent indicated by the dotted lines on the drawing.

The cradle 9 has a journalled master shaft 10 for a master cam 11. Themaster cam 11 and the roller 7 can be brought opposite each other in thesame vertical plane so that by rocking the cradle 9, the cam 11 can bebrought into contact with the follower roll 7.

The shaft 10 is axially disposed to the workpiece, not illustrated,which it is desired to present to the grinding Wheel of the customarytype as shown in the patent to Balsiger and Price, mentioned.

In order to rock the cradle 9 and thus bring the appropriate cam of theworkpiece into engagement with the grinding wheel, the cradle 9 issupplied with a rocker arm 12. The upper end of the rocker arm 12 isprovided with a recess or depression 13 on one side.

A cylinder 14 is mounted transversely of the housing opposite the headof the rocker arm 12. A piston 15 in the cylinder is provided with apiston rod 16 which extends into the headstock opposite the end of therocker arm 12. The extent of travel of piston 15 to the right isdetermined by adjusting screw 26 which abuts against the head 27 of thecylinder at the limit of movement to the right.

The piston rod 16 has a collar 17 upon the inner end.

The opposite side of the carriage has a slide bearing 18 coaxial withthe piston rod 16. A cylindrical shell 19 is slidably fitted within thebearing 18. The inner end of the cylinder 19 is attached to the collar17.

An abutment 21 has a threaded connection with the inner wall ofcylindrical shell 19 and has a reduced portion 28 also threaded toreceive member 20 which is a lock nut.

The inner end of the shell 19 is cut away as shown on the drawing toprovide clearance for the movement of the upper end of the rocker arm12.

A plunger 22 is fitted slidably into the axial bore of the abutment 21.The inner end of the plunger carries a stop or disk 23 behind anenlarged end 24 of the plunger. A compression spring 25 extends from theabutment 21 to the disk 23.

The drawing illustrates the positions of the parts with the piston 15 inits right-hand position and the cylinder 19 forcing the plunger 22against the rocker arm 12 under the pressure of the compression spring.The force exerted by spring 25 may be varied by axial adjustment of saidAt the conclusion of the grinding operation, the fluid pressure in frontof the piston 15 is reduced and the pressure applied to the right-handside of the piston thus causing the piston rod 16 to retract thecylindrical shell 19 and after the compression spring has resumed itsrelaxed position, the plunger 22 will be withdrawn from the depression13 in the rocker arm 12.

The result of this movement is to release the pressure on the rocker arm12. Continued movement of piston 15 brings collar 17 into engagementwith arm 12, and causes it to oscillate to the left, thus separating themaster cam 11 from the roller 7. During this movement the rocker armWill be free from any force applied at the upper end. However, as themovement of the piston to the left progresses, the collar 17 will thenengage the end of the rocker arm 12 and move it to the left, separatingmaster cam 11 from roller 7.

During this operation, plunger 22 is held in engagement with rocker arm12 with very light pressure, because the spring 25 is extended to itsfree length. Even this slight pressure does not resist the retractingmovement of the piston.

In the initial engagement of the rocker arm 12 by the plunger 22, thecradle is rocked to the right, but the spring 25 is not undercompression. Only after the cradle has progressed until the master cam11 cont-acts the roller 7 does the spring 25 sufier compression and thusincrease the pressure upon the rocker arm 12.

The structure as described above is an effective means for providing anunrestricted advance movement for the master cam against the followerroller and increasing the pressure through a movable advancing supportfor the actuating means. It also permits free and unrestrictedretraction of the operating means at the appropriate time.

The preferred form of the invention has been described, but it may bevaried in proportions and materials without departing from the scope ofthe invention as defined in the following claims.

What I claim is:

1. In a cam grinding machine, a work carriage, a headstock on saidcarriage, a roller shaft supported in said headstock, a roller on saidshaft, a pivot bearing on the carriage, a work cradle pivotally mountedon said bearing, a master cam rotatably mounted on the cradle oppositesaid roller, an arm on the cradle, a fluid operated piston having apiston rod movable toward and from the arm, a longitudinally movableconnecting member fixedly mounted on the piston rod, a plunger supportedon said member and compression means resiliently urging the plungertowardthe arm.

2. In a cam grinding machine, a work carriage, a headstock on saidcarriage, a roller shaft supported in said headstock, a roller on saidshaft, a pivot bearing on the carriage, a work cradle pivotally mountedon saidbearing, a master cam rotatably mounted on the cradle oppositesaid roller, an arm on the cradle, 21 fluid operated piston having apiston rod movable toward and from the arm, a

cylindrical shell having one end mounted on the piston I ton having apiston rod movable toward and from the arm, a cylindrical shell slidablysupported in the headstock with one end mounted on the piston rod, aplunger slidably carried by the opposite end of the shell, and acompression spring in the shell resiliently urging the plunger towardthe arm.

4. In a cam grinding machine, a work carriage, a headstock on saidcarriage, a roller shaft supported on said headstock, a roller on saidshaft, a pivot bearing on the carriage, a work cradle pivotally mountedon said bearing, a master cam rotatably mounted on the cradle oppositesaid roller, an arm on the cradle, a fluid operated piston having apiston rod movable toward and from the arm, a cylindrical shell havingone end mounted on the piston rod, a plunger slidably carried by theopposite end of the shell, an enlarged head on the free end of theplunger, a disk on the plunger behind the head and a compression springin the shell between the disk and the opposite end of the shell.

5. In a cam grinding machine, a work carriage, a headstock on saidcarriage, a roller shaft supported in said headstock, a roller on saidshaft, apivot bearing on the carriage, a work cradle pivotallymounted onsaid hearing a master cam rotatably mounted on the cradle oppo site saidroller, an arm on the cradle, a fluid operated piston having a pistonrod movable toward and from the arm, a longitudinally movable connectingmember fixedly mounted on said piston rod, a plunger loosely carried bysaid member with its inner end spaced from the piston rod andcompression means resiliently holding the plunger against the arm in aposition spaced from the piston rod.

6. In a cam grinding machine, a work carriage, a headstock on saidcarriage, a roller shaft supported in said head stock, a roller on saidroller shaft, a pivot bearing on the carriage, a work cradle pivotallysupported on said bearing, a master cam rotatably mounted on the cradleopposite said roller, an arm on the cradle, a piston cylindertransversely mounted in the headstock, a piston rod slidably extendingfrom the cylinder in line with said arm, a shell having one end mountedon the piston rod, a plunger slidably carried in the opposite end of theshell on the opposite side of the arm, a stop on the inner end of theplunger, and a compression spring in the shell between its end and thesaid stop.

7. In a cam grinding machine, a work carriage, a headstock on saidcarriage, a roller shaft supported in said head stock, a roller on saidroller shaft, a pivot bearing on the carriage, a work cradle pivotallysupported on said bearing, a master cam rotatably mounted on the cradleopposite said roller, an arm on the cradle, a piston cylindertransversely mounted in the headstock, a piston rod slidably extendingfrom the cylinder in line with said arm, a collar on the piston rod, aslidable shell having one end attached to the collar, a plunger slidablycarried in the opposite end of the shell, a disk on the inner end of theplunger and a compression spring in the shell between its end and thesaid disk.

8. In a cam grinding machine, a work carriage, a headstock on saidcarriage, a roller shaft supported in said headstock, a roller rotatablymounted on said shaft, a work cradle pivotally mounted on said carriage,a master cam rotatably mounted on said cradle opposite said roller andhaving a contour of varying radius, an arm on said cradle, a fluidoperated piston movable toward and from said arm, connections betweensaid piston and said arm comprising a sleeve slidably mounted in saidheadstock, a portion of said sleeve being on the opposite side of saidarm opposite said piston, an axially adjustable abutment in said sleeve,a plunger engaging said arm, a compression spring having one end inengagement with said abutment, a connection between said plunger andsaid spring, said piston, sleeve, abutment, plunger and spring beingmovable as a unit, said abutment being adjustable whereby to place saidspring under a predetermined load when the minimum radius of said mastercam is in engagement with said roller.

9. In a cam grinding machine, a work carriage, a headstock on saidcarriage, a roller shaft supported in said headstock, a roller rotatablymounted on said shaft, a work cradle mounted for transverse movement onsaid carriage, a master cam rotatably mounted on said cradle oppositesaid roller, an arm on said cradle, a fluid operated piston movabletransversely of said cradle, a plunger also movable transversely of thecradle and against said arm and a resilient connection between saidpiston and the plunger.

10. In a cam grinding machine, a work carriage, a.

work cradle pivotally mounted on said carriage and adapted to support aworkpiece, a master cam rotatably mounted on said cradle, a master camfollower on said carn'age, an operating arm on said cradle, a pistonhaving a piston rod directly engaging the arm when moving in onedirection, and resilient means carried by the piston rod for engagingthe arm when the rod is moving in the opposite direction.

References Cited in the file of this patent UNITED STATES PATENTS2,?A-3,410 Balsiger et a1 May 27, 1941

